It is sad truth that conclusions from such samples, biased or too small or both, lie behind much of what we read or think we know.

comparisons between figures with small differences are meaningless. You must always keep that plus-or-minus in mind, even (or especially) when it is not stated.

Only when there is a substantial number of trials involved is the law of averages a useful description or prediction.

The fact is that, despite its mathematical base, statistics is as much an art as it is a science. A great many manipulations and even distortions are possible within the bounds of propriety.

What’s Missing?

The point is that when there are many reasonable explanations you are hardly entitled to pick one that suits your taste and insist on it. But many people do.

To say “almost one and one-half” and to be heard as “three”—that’s what the one-dimensional picture can accomplish.

So when you see an average-pay figure, first ask: Average of what? Who’s included?

Not all the statistical information that you may come upon can be tested with the sureness of chemical analysis or of what goes on in an assayer’s laboratory. But you can prod the stuff with five simple questions, and by finding the answers avoid learning a remarkable lot that isn’t so. Who Says So?